3 files changed, 18 insertions, 26 deletions
diff --git a/vim/autoload/getenv.vim b/vim/autoload/getenv.vim
deleted file mode 100644
index 3b5f4c1b..00000000
--- a/vim/autoload/getenv.vim
+++ /dev/null
@@ -1,17 +0,0 @@
-" Backport getenv() from v8.1.1305, except return an empty string rather than
-" v:null
-"
-" <https://github.com/vim/vim/releases/tag/v8.1.1305>
-"
-function! getenv#(name) abort
-
-  if a:name !~# '^[A-Z][A-Z0-9_]*$'
-    throw 'Illegal env var name'
-  endif
-  let value = ''
-  if exists('$'.a:name)
-    execute 'let value = $'.a:name
-  endif
-  return value
-
-endfunction
diff --git a/vim/autoload/patch.vim b/vim/autoload/patch.vim
index 614be462..3a17ccda 100644
--- a/vim/autoload/patch.vim
+++ b/vim/autoload/patch.vim
@@ -6,19 +6,27 @@
 "
 function! patch#(version) abort
 
-  " If we're new enough, we can just use the native has()
+  " If the Vim running is new enough for its has() function to support
+  " checking patch levels with version prefixes, we can just add a "patch-"
+  " prefix to the query, and pass it on to has().
+  "
   if has('patch-7.4.237')
     return has('patch-'.a:version)
   endif
 
-  " Otherwise, we need to start splitting and comparing numbers
+  " Failing that, we need to do our own version number and patch number
+  " comparisons; split the queried version on dots.
+  "
   let [major, minor, patch] = split(a:version, '\.')
 
-  " The v:version variable looks like e.g. 801 for v8.1
+  " The internal variable v:version describing the running Vim looks like
+  " e.g. 801 for v8.1; reproduce that logic for the queried version.
+  "
   let l:version = major * 100 + minor
 
-  " If the version numbers are the same, return whether we have the patch;
-  " otherwise, return whether the version
+  " If the running version number is the same as the required one, return
+  " whether we have the specific patch requested; otherwise, return whether
+  " the running version number is greater than the required one.
   "
   return v:version == l:version
         \ ? has('patch-'.patch)
diff --git a/vim/autoload/xdg.vim b/vim/autoload/xdg.vim
index c5737506..67a9c5b2 100644
--- a/vim/autoload/xdg.vim
+++ b/vim/autoload/xdg.vim
@@ -12,10 +12,11 @@ function! s:Get(name) abort
   if !has_key(s:defaults, name)
     throw 'Illegal XDG basedirs env var name'
   endif
-  let value = getenv#(name)
-  return value !=# ''
-        \ ? value
-        \ : s:defaults[name]
+  let value = s:defaults[name]
+  if exists('$'.a:name)
+    execute 'let value = $'.a:name
+  endif
+  return value
 endfunction
 
 function! s:Absolute(path) abort